This invention relates to rotary compressor units, and more particularly to a horizontal type compressor unit provided with a lubricating oil pumping mechanism including fluid diode check valves.
Ordinarily, a vertical type rotary compressor unit has been used in a refrigerating apparatus. However, the rotary compressor unit comprising an electric motor and a rotary compressor vertically disposed in a casing has a height substantially larger than the diameter thereof. Thus, when the rotary compressor unit is incorporated into a refrigerating apparatus of a horizontally elongated construction, the arrangement of the parts of the apparatus is restricted by the height of the vertical rotary compressor unit.
Furthermore, the electric motor and the compressor are ordinarily fixed rigidly to the internal structure of the casing, and therefore severe vibrations tend to be created, particularly when the rotary compressor is of a single vane type. The vibration inevitably creates noise, and often breaks pipe connections between the compressor unit and various parts of the refrigerating apparatus, resulting in a leakage of the refrigerant gas.
In order to eliminate the above described disadvantages of the vertical type compressor unit, there has been proposed a horizontal type compressor unit wherein the compressor and the electric motor are disposed horizontally. In this type of the rotary compressor unit, there is included a rotary compressor comprising a rotor rotatable in a cylinder, a blade held in contact with the outer surface of the rotor and reciprocates in a radial direction in the cylinder, a chamber defined by end plates longitudinally spaced apart on both sides of the cylinder, suction and discharge passages opening through the end plates into the closed chamber, and a check valve provided at least in the suction passage.
However, since the check valve of the conventional compressor unit is of a mechanical type, various disadvantages such as creating noise, rapidly wearing, and difficulties in installation and repair are caused.